Medical catheters, guide catheters and guide tubes are used for innumerable minimally-invasive medical procedures, wherein a tube is inserted into a lumen in a patient's body, such as a blood vessel, and maneuvered to a target site, such as a heart chamber or another blood vessel. These catheters and guide tubes may be used as conduits for a variety of medical procedures, including delivery of therapeutic drug doses to target tissues, delivery of medical devices such as lumen-reinforcing or drug-eluting stents, and guiding medical instruments to a target site to perform a surgical procedure, such as tissue rescission, ablation of obstructive deposits or myocardial revascularization.
In order to accurately maneuver a catheter or similar medical device (such as a guide tube or a guide wire) through a body lumen to a target site, means of ascertaining the location and orientation of the device are needed. A frequently used imaging technique employs fluoroscopy to image the device.
Maneuvering and placement of medical devices such as catheters frequently requires imaging from multiple angles or with multiple imaging devices. This is necessary in order to obtain an adequate image of the target site and the device, and to verify that the device is oriented in the desired direction, i.e., to verify that the tube is not, for example, rotated into a position which appears to be correct when viewed by fluoroscopy from one direction, but is in fact rotated about a plane of imaging away from the desired orientation, e.g., positioned away from instead of toward the imaging equipment, or vice-versa. The need for multiple views of the device increases the complication, time and expense of a medical procedure, as either multiple fluoroscopes must be employed to obtain the desired views, or a single fluoroscope must be sequentially set up, used, repositioned, etc. to provide adequate imaging coverage. Alternative imaging techniques that may provide higher resolution in the future have demonstrated some potential (such as MRI-based catheter imaging techniques); however, such developments have not as yet advanced to the point of regular clinical use or undesirably add cost, large, bulky equipment and/or additional imaging set-up and use time to the overall procedure.
Thus, there is a need for a simplified, reliable method and system for guiding medical devices such as catheters to a target site within a patient and ensuring the distal end of such devices are properly located and oriented at a target site.